As the presidents of the three largest police unions in the Bay Area, our overriding responsibility is to ensure that each and every police officer we represent makes it home to his or her family after every shift. Police officers must swear to uphold the Constitution, and we also take seriously our responsibility to protect the First Amendment rights of the public we serve. Unfortunately, recent events threaten to bring these two great responsibilities into conflict.

Our members and their families have been shaken to the core by the brutal slayings of two New York City police officers and a Tarpon Springs, Fla., police officer. All of our members are on heightened alert. In-the-line-of-duty deaths of police officers are up significantly: 123 police officers have already paid the ultimate price for protecting their communities in 2014.

The protests that followed the grand-jury decisions in Missouri and New York are a legitimate expression of our First Amendment traditions. The reaction is not unexpected but the vilification of law enforcement officers by some politicians and media pundits has been demoralizing and unjust. Public safety in the Bay Area and the nation will be a subject of major debate going forward. We will each participate vigorously in that debate.

But what few have acknowledged until now is that too often the legitimate expression of views has devolved into vilification and violence against this nation’s front-line public safety servants. Demonstrators in New York chanted in unison: “What do we want? Dead cops! When do we want it? Now!” That was disgraceful. So, too, was witnessing protest marches in the Bay Area degenerate into violence, destruction and mob rule. Despite the efforts of organizers, too often protests were hijacked by shameful cowards who take refuge behind the truly law abiding demonstrators while destroying property and injuring our officers.

The overwhelming majority of our members — who represent the most diverse police departments in the nation — bear such malice in dignified silence. Even following the killing of three of their own, our officers continue with their duty, answer your calls, respond to your crises, fulfill their mission, and honor their commitment to the people of San Francisco, San Jose and Oakland.

In short, they will always be there when you need them. In return, as their voices, we simply ask that you join them in a cooperative effort to keep our streets safe, and to engage in constructive dialogue that calls for a commonsense approach to very complex issues.

May we all take this holiday season as a time to reflect and pray for one another and search for solutions together as the law enforcement community honors those who have fallen in the line of duty.

Martin Halloran is the president of the San Francisco, Paul Kelly is the president-elect of the San Jose and Barry Donelan is the president of the Oakland police officers associations.